Abstract Detail

Genetics

Barthet, Michelle Marie [1], Pierpont, Christopher Logan [1].

The impact of RNA editing and position of N-terminus on MatK maturase activity.

MatK, the protein product of the plastid matK gene, is postulated to function as the only plastid-encoded group II intron maturase in the plant cell. Maturases are enzymes that remove introns from precursor RNAs and, thus, play a significant role in the process of gene expression. Unlike prokaryotic maturases which typically bind to and excise a single target intron, the MatK maturase binds to seven target introns. These introns reside within transcripts for essential RNAs and proteins of the plastid translation complex implicating MatK as a vital enzyme of the plant cell. Contrary to the importance of MatK in plastid function, the matK gene has a remarkably high synonymous and nonsynonymous substitution rate for a protein-coding gene. In addition, the N-terminus of MatK has been found to be variable in some plant families such as the Orchidaceae. These unusual characteristics, high substitution rate, variable N-terminus, and unique ability to bind multiple-intron targets, suggest altered mechanisms for expression and function of this important maturase. The goals of the current investigation are to discern the impact of RNA editing, as well as length of N-terminus, on MatK expression and activity and determine associated factors required for complete group IIA intron removal in the plant plastid. We have identified up to five RNA edited sites in matK cDNA from Oryza sativa which may combat otherwise deleterious nucleotide changes from genomic DNA. matK cDNA containing various levels of RNA editing as well as altered N-termini have been cloned to test the impact of these alterations on MatK protein expression and function. Results of this work will be discussed along with future implications of MatK in plastid splicing processes.

1 - Coastal Carolina University, Biology, 111 East Chanticleer Drive, Conway, SC, 29526, USA

Keywords:
MatK
maturase
plastid
splicing
RNA editing.

Presentation Type: Oral Paper
Session: 11, Genetics
Location: 105/Savannah International Trade and Convention Center
Date: Monday, August 1st, 2016
Time: 4:00 PM
Number: 11010
Abstract ID:192
Candidate for Awards:Margaret Menzel Award